FIG. 2.

A reduced model of viral dynamics. The time courses of virus growth and decay (A) and CD4⁺ T-cell (target cell) decline in primary infection (B) are shown, obtained by numerical integration of equation 1 to equation 3 and equation 7 to equation 9. (A) The peak viral loads for the reduced model (λ, d_T = 0) and the standard model (λ = 10 cells/μl/day; d_T = 0.01 day⁻¹). (B) The nadir numbers of uninfected CD4⁺ T cells are indicated for the reduced model and the standard model. The total CD4⁺ T-cell number (infected plus uninfected) is also indicated for the standard model. The other parameters were as follows: β = 8 × 10⁻⁸ ml/copy/day, δ = 0.8 day⁻¹, P = 10³ μl/ml × 500 copies/cell/day, and c = 20/day. The initial inoculum was 50 copies/ml.